1. Field of the Invention
The useful apparatus of the instant invention is concerned with an automated delivery system. More particularly it is concerned with the use of gas fluidic circuitry in combination with appropriate mechanical devices to sequentially transfer samples from a sample holding means to an NMR spectrometer and back to such means after the NMR analysis is complete.
2. Prior Art
Automated delivery systems are old in the art. Devices and apparatus for transferring samples from a sample holding means to an instrument for an analysis of such samples are also old in the art. Mechanical, electrical, electronic, and liquid hydraulic means, and combinations thereof, have been adapted to systems for transferring samples, and containers thereof, to and from instruments which analyze various characteristics of such samples.
NMR spectrometry is a means for determining various molecular substituents present in a sample by using magnetic fields and radio frequency (RF) radiation to examine the molecular structure of constituents present in standard solutions. The sample to be analyzed is introduced into the spectrometer in a solution disposed in a specially designed container which can be rotated (spun) in an RF field, and by observing the frequencies at which the RF is absorbed, certain characteristics of the molecular structure can be determined.
Inasmuch as the NMR analytical technique involves a magnetic field it is imperative that no stray electromagnetic forces are generated in the field in which the sample is disposed. Consequently, electrical and electronic means for operating an automated sample transfer system with an NMR spectrometer are not favored because of the need to shield the system to prevent stray magnetic radiation. Pure mechanical systems are bulky, cumbersome and slow. Liquid hydraulic systems are also bulky and limited in their applications where liquids do not present a contamination problem as are combinations of liquid hydraulic and mechanical systems.
Accordingly, it is an object of this invention to provide an automated apparatus that is totally free of all extraneous magnetic fields for sequentially transferring samples to and from an NMR spectrometer.
It is another object of the instant invention to combine gas fluidic circuitry with appropriate mechanical devices to provide a reliable automated apparatus that is compact, self-sensing and responsive to integrated fluidic circuitry that utilizes low pressure gas to propel the mechanical parts of the apparatus as well as to sense the sequence of the operation of such mechanical parts for sequentially transferring samples to and from an NMR spectrometer.